Pump unit



E. G. VEJDE June 8, lv1965 PUMP UNIT Filed July 17, 1963 United States Patent O 3,187,675 PUlVlP UNIT Emst Gran Vejde, Furusundsgatan, Stockholm, Sweden Filed July 17, 1963, Ser. No. 295,737 5 Claims. (Cl. 10S-S7) rfhe present invention is related to la pump unit having an impeller driven fby an electric motor 'and in particular to a pump unit usable Ias -a submersible sinking pump, hore hole pump lor hilge pump. For such a pump unit it is essential that it `can work `at a very small liquid depth and that the pump unit has va diameter vas small as possi-ble.

It is known in the :art to provide a pump unit for this punpose with a substantially cylindrical pump |housing which is provided with an inlet opening at the one end and an outlet opening at the other end and in which `an electric motor with yan impeller attached `to one end of Ithe motor shaft is disposed coaxially to fthe symmetry 4axis of the pump housing so that an annular space of substantially .uniform ibreadth is formed lbetween the motor and the pump housing, :said space ffonming a duct from the inlet opening Eto the 'outlet opening of the housing hor the liquid [being pumped. In such a pump the impeller is normally attached -to the end of the shaft of the electnic 3,l87,675 Patented June 8, 1965 ICC tween this end of the motor and the housing -a space is formed having substantially fthe same lform as the surface area between two eccentric circles one of them enclosing the other, Ithe outlet opening [from `the housing heing located at this last-mentioned space.

In a preferred embodiment fot the invention the end of the motor disposed eccentrically in the housing is so located that its circumference is substantially tangential to the inner wall of the pump housing in one point, whereby the space formed lbetween this end of the motor and the housing will have substantially the it'onm of -a moons sickle. With the motor disposed within the .pump housing' in the manner according `to the invention it lbecomes possible tto arrange the outlet opening of the housing in such a 'Way that it -is located entirely within the circumsoription of the lspace lbetween the pump housing and the end of the motor Vlocated eccentrically within lthe housing.

In ia pump unit according to the invention the maximum diameter of the pump unit is consequently, just as in pump units of the type previously known, determined by the j diameter of the motor and the breadth of the space around motor which is `adjacent to the inlet opening of the pump and the Ibreadth of the -annular duct around the motor for the liquid ibeing pumped. In order to avoid that the width .of the pump unit at Aany point exceeds this smallest necessary diameter, the outlet opening `trom the pump housing and the devices for connecting a pressure pipe or hose to the pump must, however, he disposed at the one end surface of 'the pump housing and entirely within the circumference of the pump housing determined by said smallest necessary diameter. yAs however the diameter of the outlet .opening yand of the pressure cond-uit connected to the pump unit must be considerably larger than the breadth ot lthe annular duct lon the Ioutside of the motor, it will lbe necessary that the outlet opening and the connecting means for the pressure conduit are located partly or entirely albove the end fsunface of the motor which is opposite to the impeller. This involves, however, the substantial disadvantage that the motor will not he accessible ior inspection or repair or replacement, Without the pressure conduit connected to the pump unit as well as the end plate `off fthe pump housing ycomprising the outlet lopening heing previously dismounted. Further it will not be possible to use an electric motor vof standard type, as the end shield of the motor :opposite to the impeller should preferably ibe so designed that it also comprises the outlet opening of the pump unit and 'the coupling means for the lconnection of -a pressure conduit or hose to the pump unit.

The Iobject of fthe present invention iis to provide an improved pump unit of the type described above, which does not suiier from lthe laibovementioned disadvantages. With this object in view lthe electric motor with the impeller attached to one end 'of the motor shait in 'a pump unit of the type referred `to is according to the invention so disposed within the pump housing that the symmetry axis of the motor forms yan acute angle with the symmetry axis of the pump housing and that the end of the motor adjacent to the impeller is llocated substantially concentric in the housing so that an Iannular space having a substantial-ly uniform hreadth is formed between this end ci the motor and the housing, Whereas the opposite end of the motor is located eccentric in the housing so that he` the end of the motor `adjacent to the impeller necessary for lthe liquid heing pumped, due to which the maximum diameter 101i .the pump unit will ibe as small as possible. In spite of this the end ofthe motor opposite Ito `the impeller Will, due to -the yfact that the motor is disposed in the pump housing in the manner according to the invention, lbe easily accessible from the outside off the pump unit, as this end of the motor is not to any part covered hy the `outlet yopening lfrom the .pump unit or by the pressure -conduit or hose connected to the pump unit. In -a pump unit according to the invention it is consequently possible to inspect the motor or remove it Ltr-om the pump housing e.g. [for replacement of the motor or inspection of the interior :of the pump housing, without any other parts of the pump uni-t having .to be previously dismounted. Further :according to Kthe invention the electric supply conductors and the connection terminal iboard yfor the electric motor may he .arnanged at the end of the motor opposite to the impeller 'and entirely lwithin the circumference of the motor. The motor can consequently dorm `a separate unit independent of and removable from the remaining part of the pump unit, due Ito which a motor of standard type can be used.

In the [fol-lowing the invention will be iurther described with reference to the enclosed drawmg, wherein `FIGURE 1 is a sectional View of la pump unit according to the invention;

FIGURE 2 is Ia sectional view `taken along line II--II in FIG. l; `and FIGURE 3 is a section taken along line III-III in FIG. 1.

F or the sake oi simplicity no details within the motor casing -of the pump unit are shown in FIGS. 2 and 3.

The pump unit shown in the drawing comprises a cylindrical pump housing 1 having an outlet 'opening 2 at its upper end and a connection element 3 ttor a pressure pipe or hose. At its lower end the pump housing '1 is provided with `an inlet opening 4 :and a suction basket 5. The peripheral wal-1 of Vthe suction Ibasket is provided with openings 6, through which the liquid ibeiug pumped by the pump unit ilows into Vthe pump. The pump unit can consequently operate when standing on its lower end snrface in the manner normally used for submersible sinking pumps or bi lge pumps. The pump unit comprises also Ian electric motor 7 with a cylindrical motor casing 13, a stator core -14 with a stator winding 15, a rotor :16 yand a rotor shaft 17. The rotor shaft y17 projects mthr-ough one oi' the end sunfaces of the motor casing 13 and an impeller 8 is yatt-ached to the end of the rotor shait 17. The

motor '7 is disposed substantially completely within the* pump casing 1 in sucha way that a tluid passage 18 leadk forms an acute angle withjthe yaxis of symmetry of the pump casing =1 with the end of the pump casing 13, -adjacent the impeller 8, lying substantially centrally Within the pump casing. The opposite end of the motorcasing 13 lies eccentrically within the'pnmp casing 1 and is tangent to the inner cylindrical surface of the pump casing 1. In this -Way the Huid passage 18 will at the lower'end of the motor casing 13 near the yimpeller 8 have an annular cross-section with a substantially uniform breadth, `as illustrated inFIG. 2, whereas at the upper end of the motor casing near to the outlet opening 2.,4 the passage 18 will have a crescent-shape cross-section as illustrated in FIG. 3. As a result of this arrangement of the motor within the pump casing, -t-he outlet opening 2 from the pump casing can be disposed entirely within the circumscniption of the cross-section of the passage 18 at this end of the pump casing. Consequently, it is not necessary to increase the overall diameter of the pump casing at this outletend and l'the upper end sunface of the motor 7 will not to any part Ibe covered by the outlet opening of the pump housing or by the connectionmeans for coupling a pressure conduit -or hose. to the pump unit, but will tbe immediately accessible from the outside of the pump unit, without any u part of the pump `unit having to be dismounted. In a pump unit according to the invention it is yfurther possible to dispose the electric supply conductors for the motor t 7 and :a connection terminal tboard 1i1 at 'the lupper end sunface of the motor and entirely within the circumference of the motor. By removing only the upper end shield 12 of 4the motor the motor can tbe readily inspected without any other parts of the pump unit havingto be dismounted. Due to this the maintenance of the pump unit is considerably facilitated, since lit is principally the motor of the pump unit which requires maintenance or replacement. Since in the pump unit according to the invention,

4 to the outlet opening of the What I olairn is:

1. A pump unit comprising a substantially cylindrical pump casing having an inlet a-t one end and an out-let at an opposite end, an electric motor with a substantially cylindrical motor casing having 4a first end and a second end and a rotatable shaft driven by said motor projecting from said motor casing through said -tirst end thereof, an impeller attached to said projecting shafft, said motor with said motor casing being disposed within said pump casing with said iirst end of said motor casing and said impeller attached to said shaft projecting through said irst end facing the linlet end of said pump casing, said pump casing and the motor casing defining therebetween a iiuid passage which leads from said inlet to said outlet, said motor casing being disposed within saidtpump casingl with the axis of symmetry o'f the motor casing extending at an acute angle relative to the yaxis of symmetry of said pump casing and with said iirst end of said motor casing lying substantially centrally Wit-hinV said pump casing and said `second end of said motor casing lying eccentrica'lly within said pump casing such that at said irst end of said motor casing said fluid passage has -an annular crossJsection with a substantially uniform breadth and at said second end of said motor casing said fluid passage has a cross-section of varying breadth, said outlet of said pump casing being located at Ithe latter cross-sectionof said passage.

2. YA pump unit 'as claimed in claim 1, wherein said second end of said motor casing is tangent to said pump casing whereby at said second end of said motor` casing said fluid passage has a crescent-shape cross-section.

f3. A pump unit as claimed in claim 2, wherein said outlet opening of said pump casing is disposed entirely 1 within the circumscription of the cross-section of sa'id the motor'7 may form a separate unit independent of any other parts of the pump unit, a motor of standard type can be used.

The invention is, however, of course` not limited to exactly the pump shown in the enclosed drawing. Thus, the invention is applicable not only to submersible sinking pumps or bilge pumps or the like ibut lalso to normal pump units rforming a part of -a permanent system of liquid conduits. Also this embodiment of the invention has the pronounced advantage that the `driving electric motor of the pump unit can be easily andswiftly dismounted from the pump unit, e.g. for repair or replacement, withoutany other parts of the pump unit or any pant of lthe permanent conduit network connected to the pump unit having to be dismounted,

uid passagerat said second end of said motor casing.

4.v A pump :unit ias claimed in claim 1, comprising electrical supply conductor means yand electrical terminal means for said motor, said supply conductor means and terminal means being mounted on said motor casing at said second end thereof entirely Within the enclosure of said second end of said motor casing.

5. A pump unit as claimed in claim l1, wherein said second end of said motor casing projects beyond said outlet end of said pump casing.

References Cited bythe Examiner UNITED` STATES PATENTS 1,528,083 3/25' Schmidt -103-87 FOREIGN PATENTS 893,675 10/44 France.

65,309 3/50 Netherlands..

LAURENCE V. EFNER, Primary Examiner.

ROBERT M. WALKER, Examiner, 

1. A PUMP UNIT COMPRISING A SUBSTANTIALLY CYLINDRICAL PUMP CASING HAVING AN INLET AT ONE END AND AN OUTLET AT AN OPPOSITE END, AN ELECTRIC MOTOR WITH A SUBSTANTIALLY CYLINDRICAL MOTOR CASING HAVING A FIRST END AND A SECOND END AND A ROTATABLE SHAFT DRIVEN BY SAID MOTOR PROJECTING FROM SAID MOTOR CASING THROUGH SAID FIRST END THEREOF, AN IMPELLER ATTACHED TO SAID PROJECTING SHAFT, SAID MOTOR WITH SAID MOTOR CASING THROUGH SAIDFIRST END THEREOF, CASING WITH SAID FIRST END OF SAID MOTOR CASING AND SAID IMPELLER ATTACHED TO SAID SHAFT PROJECTING THROUGH SAID FIRST END FACING THE INLET END OF SAID PUMP CASING, SAID PUMP CASING AND THE MOTOR CASING DEFINING THEREBETWEEN A FLUID PASSAGE WHICH LEADS FROM SAID INLET TO SAID OUTLET, SAID MOTOR CASING BEING DISPOSED WITHIN SAID PUMP CASING WITH THE AXIS OF SYMMETRY OF THE MOTOR CASING EXTENDING AT AN ACUTE ANGLE RELATIVE TO THE AXIS OF SYMMETRY OF SAID PUMP CASING AND WITH SAID FIRST END OF SAID MOTOR CASING LYING SUBSTANTIALLY CENTRALLY WITHIN SAID PUMP CASING AND SAID SECOND END OF SAID MOTOR CASING LYING ECCENTRICALLY WITHIN SAID PUMP CASING SUCH THAT AT SAID FIRST END OF SAID MOTOR CASING SAID FLUID PASSAGE HAS AN ANNULAR CROSS-SECTION WITH A SUBSTANTIALLY UNIFORM BREADTH AND AT SAID SECOND END OF SAID MOTOR CASING SAID FLUID PASSAGE HAS A CROSS-SECTION OF VARYING BREADTH, SAID OUTLET OF SAID PUMP CASING BEING LOCATED AT THE LATTER CROSS-SECTION OF SAID PASSAGE. 